In recent years, with improvement in the degree of semiconductor integration, a system integrated into LSI has become larger in scale and more complicated. As a result, the design time has increased, and also the incidence of unavoidable design defects in software has increased. In the market, however, demands have been made for further reduction in turnaround time (TAT) (shortening of the design time of a new product) and higher quality design.
To address the above problem, there is known a technology in which a reconfigurable semiconductor integrated circuit is used to contribute to shortening of the design time and reduction in the number of defects. A reconfigurable semiconductor integrated circuit includes programmable logic devices represented by recently available field programmable gate arrays (FPGAs). As described in Non-Patent Literature 1, for example, a programmable logic device is an integrated circuit, provided with a plurality of logic elements, which can implement any given processing function by changing the processing functions of the logic elements and the connection states between the logic elements. A plurality of such programmable logic devices are connected to each other to complete a reconfigurable semiconductor integrated circuit. Once such a reconfigurable semiconductor integrated circuit is completed as a device, how to assign processing for the device to execute the processing can be done only by software. This makes it unnecessary to design both hardware and software, and thus shortens the design time. As another advantage, since all the processing functions are implemented by software, only correction of software will suffice if a defect happens to occur.    Non-Patent Literature 1: “Douteki saikouseikanou device—sono sujou to jitsuryoku (Dynamic reconfigurable device—Its origin and capability)” edited by Design Wave Magazine, pp. 19-29, August 2004